1. Technical Field
The disclosure relates to a preparation method of core-shell microstructures. More particularly, the disclosure relates to a preparation method of core-shell microstructures without adding emulsifier.
2. Description of Related Art
Recently, polymer spheres are more widely applied with the progress of the design and synthesis of the polymer spheres. Generally, the surfaces of the polymer spheres can be chemically modified to have various functional groups for applying in various fields, such as oil paintings, cosmetics, drugs spacers of LCDs, and photonic crystal, etc.
In the prior arts, emulsion polymerization is usually used to prepare polymer spheres. However, the problem of emulsifier remnant limits the applicable fields of the polymer spheres. For solving the problem above, an emulsion polymerization without adding emulsifier was developed. However, when polymer spheres with core-shell structures need to be prepared, an emulsion of polymer spheres needs to be prepared first. Then, the polymer spheres are used as seeds to prepare shells enclosing the polymer spheres by seeded swelling polymerization. In more particularly, in the above seeded swelling polymerization, a shells monomer and a swelling agent have to be added to the emulsion of the polymer spheres at a certain temperature to swell the emulsion. Then, an initiator was added to start polymerizing the shell monomer. In addition to prepare the emulsion of polymer spheres in advance, the swelling time needed is about one day. Therefore, the preparation time is too long and the cost is thus too high. Accordingly, the seeded swelling polymerization is not suitably used to commercialize the preparation of the polymer spheres with core-shell structure and surface chemical modification.